Lockdown cycles

The appearance of SARS CoV-2 has been deemed worthy of extraordinary measures to contain or suppress its spread. With a rise in infections across Europe, politicians are once again scrambling to reintroduce a series of policies that amount to lockdown in all but name. France has introduced a curfew. Italy has made the wearing of masks mandatory outdoors. And London’s nine million residents have been banned from meeting people they don’t live with indoors. Such extraordinary measures imply that the epidemic of SARS-CoV2 has features that are out of the ordinary when compared to previous pandemics. But is this right? Or are we setting a precedent for the way we deal with infectious diseases?

We are, of course, all familiar with acute respiratory infections and their effects. They are a seasonal nuisance; occasionally they can put us into hospital, or even worse, speed our departure. A host of known pathogens circulate across different parts of the year and some – 40 per cent – cannot be identified. Each infectious pathogen, generally, has its seasonal window. In the northern hemisphere, influenza occurs each winter; chickenpox tends to peak in spring; and in the past, polio occurred in late summer and autumn. The four human coronaviruses that already circulate are also seasonal. A US study that followed over a thousand individuals for eight years found they are most common between December and May, with only 2.5 per cent of infections occurring between June and September. Why would it be assumed that Covid-19 be any different?

Historically, seasonal pathogens have been dealt with by either monitoring them or by vaccination of those most vulnerable. Licensed vaccines are, however, only available against one of the many agents: influenza. The last pandemic was swine flu in 2009. It was not as severe as initially thought, in part, because older people were found to have population immunity. Today the swine flu virus is seasonal and is often included in the annual influenza vaccine to mitigate its effects.

The World Health Organisation was criticised for having exaggerated the threat of swine flu. This resulted in the creation of a little known instrument to grade pandemic severity, the Pandemic Influenza Severity Assessment (PISA). PISA sets out three indicators for assessing severity when sustained human-to-human transmission occurs: transmissibility of the virus, the seriousness of the disease and its impact.

Novelty does not feature as an indicator, but the number of cases – transmissibility – does. The document does not set thresholds and leaves each country to develop its own based on historical data and precedent. The past has all been about influenza, where the historical threshold has been around 400 primary care consultations per 100,000 registered patients. If you set your threshold as low as 50 cases of infection per 100,000 people (irrespective of whether they are ill or not) as appears to be the case with Covid-19, then you have a problem. Why? Because in autumn – as soon as schools and universities go back – you’ll rapidly exceed that threshold.

In terms of Covid’s seriousness, even though the mortality rate is difficult to ascertain with precision, it appears to be increasingly comparable with the worst of the acute infections. The daily diet we are fed, however, of Covid deaths is distorting our ability to understand the real impact of the disease. Without the context of what happens throughout the seasons, the policy is, unsurprisingly, confused, contradictory and often reaches the wrong decision.

Given that Covid does not appear to have a vastly higher mortality rate than that linked to other common circulating pathogens then, we need to ask ourselves: what are the long-term consequences of the ‘special attention’ paid to Covid-19?

The first and most apparent is that influenza is not the only infectious agent and that there are many more nasty customers out there, some of which we know nothing about. The second consequence is the heightened sensitivity around what was – until February this year – considered everyday nuisances: it’s the ‘flu season’ as we once knew it. Third, we are now used to various public health policies affecting whole populations made on little or no evidence. 

This could set a worrying precedent. The current events are leading us into a cycle of lockdown. There is little attention being paid to the seasonal effect and the endgame. If a ‘circuit breaker’ is adopted, what happens when this ends in three weeks? Previous coronaviruses have circulated until spring, and the current Covid virus seems to be operating similarly.

If we do not account for the ‘lockdown cycle’ then the logical consequence could be a never-ending circle of closing and opening of society, probably local and possibly national with unforeseen consequences. This cycle has already begun, and with such low thresholds for intervening and high sensitivities for Covid-19, it is likely to continue.

Logic has played little part in all this; short-termism has dominated the strategic decisions so far. And as Covid fatigue sets in, we need a long-term plan that controls the impact of the disease while minimising the disruption for the wider society. If we don’t, then we need to prepare ourselves to get ready for the annual policy merry go round with its possible benefits and certain harms.